package cn.wl.gulimall.product.service.impl;

import cn.wl.gulimall.product.service.CategoryBrandRelationService;
import cn.wl.gulimall.product.vo.Catelog2Vo;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.aliyuncs.ecs.model.v20140526.DescribeInvocationResultsResponse;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.cache.annotation.Caching;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import cn.wl.common.utils.PageUtils;
import cn.wl.common.utils.Query;

import cn.wl.gulimall.product.dao.CategoryDao;
import cn.wl.gulimall.product.entity.CategoryEntity;
import cn.wl.gulimall.product.service.CategoryService;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.StringUtils;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Autowired
    CategoryBrandRelationService categoryBrandRelationService;
    @Autowired
    StringRedisTemplate redisTemplate;
    @Autowired
    RedissonClient redisson;

//    private Map<String,Object> cache = new HashMap<>();

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        //1.查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);

        //2.组装成父子的树形

        //2.1找到所有的一级分类
        List<CategoryEntity> level1Menus = entities.stream().filter(item -> item.getParentCid() == 0)
                .map(menu -> {
                    menu.setChildren(getChildrens(menu, entities));
                    return menu;
                })
                .sorted((menu1, menu2) -> {
                    return (menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort());
                })
                .collect(Collectors.toList());

        return level1Menus;
    }

    @Override
    public void removeMenusByIds(List<Long> asList) {
        //TODO 检查当前删除的菜单，是否被别的地方引用


        baseMapper.deleteBatchIds(asList);
    }

    @Override
    public Long[] findCatelogPath(Long catelogId) {
        List<Long> paths = new ArrayList<>();
        List<Long> parentPath = findParentPath(catelogId, paths);
        Collections.reverse(parentPath);
        return parentPath.toArray(new Long[parentPath.size()]);
    }



    @Caching(evict = {
            @CacheEvict(value = "category",key = "'getLevel1Categorys'"),
            @CacheEvict(value = "category",key = "'getCatalogJson'")
    })
    //级联更新所有关联的数据
    @Transactional
    @Override
    public void updateCascade(CategoryEntity category) {
        this.updateById(category);
        categoryBrandRelationService.updateCategory(category.getCatId(), category.getName());
    }

    //每一个需要缓存的数据我们都来指定要放到那个名字的缓存。【缓存的分区（按照业务类型分）】
    @Cacheable(value = {"category"},key="#root.method.name")  //代表当前方法结果需要缓存，如果缓存中有，方法不用调用，如果缓存中没有，调用方法，最后将方法的结果放入缓存
    @Override
    public List<CategoryEntity> getLevel1Categorys() {
        long eee = System.currentTimeMillis();
        List<CategoryEntity> parent_cid = this.list(new QueryWrapper<CategoryEntity>().eq("parent_cid", 0));
        System.out.println("消耗时间:" + (System.currentTimeMillis() - eee));
        return parent_cid;
    }

    @Cacheable(value = "category",key = "#root.methodName")
    @Override
    public Map<String, List<Catelog2Vo>> getCatalogJson(){
        System.out.println("查询了数据库.......");
        List<CategoryEntity> selectList = baseMapper.selectList(null);
        //查出所有1级分类
        List<CategoryEntity> level1Categorys = getParent_cid(selectList, 0L);
        Map<String, List<Catelog2Vo>> parent_cid = level1Categorys.stream().collect(Collectors.toMap(k -> k.getCatId().toString(), v -> {
            //1.每一个一级分类，查到这个一级分类的二级分类
            List<CategoryEntity> categoryEntities = getParent_cid(selectList, v.getCatId());
            //2.封装上面的结果
            List<Catelog2Vo> catelog2Vos = null;
            if (categoryEntities != null) {
                catelog2Vos = categoryEntities.stream().map(l2 -> {
                    Catelog2Vo catelog2Vo = new Catelog2Vo(v.getCatId().toString(), null, l2.getCatId().toString(), l2.getName());
                    //1.找当前二级分类的三级分类封装成vo
                    List<CategoryEntity> level3Catelog = getParent_cid(selectList, l2.getCatId());
                    if (level3Catelog != null) {
                        List<Catelog2Vo.Catelog3Vo> collect = level3Catelog.stream().map(l3 -> {
                            //2. 封装成指定格式
                            Catelog2Vo.Catelog3Vo catelog3Vo = new Catelog2Vo.Catelog3Vo(l2.getCatId().toString(), l3.getCatId().toString(), l3.getName());
                            return catelog3Vo;
                        }).collect(Collectors.toList());
                        catelog2Vo.setCatalog3List(collect);
                    }

                    return catelog2Vo;
                }).collect(Collectors.toList());
            }
            return catelog2Vos;
        }));
       return parent_cid;
    }

    //TODO 产生堆外内存溢出：OutofDirectMemoryError

    public Map<String, List<Catelog2Vo>> getCatalogJson2() {
        //给缓存中放json字符串，拿出的json字符串逆转为能用的对象类型【序列号与反序列化】
        //1. 加入缓存逻辑,缓存中存的数据是json字符串
        //JSON跨语言，跨平台兼容
        /**
         * 1.空结果缓存：解决缓存穿透
         * 2.设置过期时间（加随机值）：解决缓存雪崩
         * 3.加锁：解决缓存击穿问题
         */
        String catalogJson = redisTemplate.opsForValue().get("catalogJson");
        if (StringUtils.isEmpty(catalogJson)) {
            System.out.println("缓存不命中。。。查询数据库");
            //2.缓存中没有,查询数据库
            Map<String, List<Catelog2Vo>> catalogJsonFomdb = getCatalogJsonFomdbWithRedisLock();
            //3.查到的数据再放入缓存,将对象转为json放在缓存中
            return catalogJsonFomdb;
        }
        System.out.println("缓存命中。。直接返回");
        //转为我们指定的对象
        Map<String, List<Catelog2Vo>> result = JSON.parseObject(catalogJson, new TypeReference<Map<String, List<Catelog2Vo>>>() {
        });
        return result;
    }

    public Map<String, List<Catelog2Vo>> getCatalogJsonFomdbWithRedissonLock() {
        //1. 锁的名字，粒度越细越快
        //锁的粒度:具体缓存的是某个数据，11号商铺；product-11-lock
        RLock lock = redisson.getLock("catalogJson-lock");
        lock.lock();
        Map<String, List<Catelog2Vo>> dataFromDb;
        try {
            dataFromDb = getDataFromDb();
        } finally {
            lock.unlock();
        }
        return getDataFromDb();
    }

    public Map<String, List<Catelog2Vo>> getCatalogJsonFomdbWithRedisLock() {
        //1.占分布式锁,去redis占坑
        String uuid = UUID.randomUUID().toString();
        Boolean lock = redisTemplate.opsForValue().setIfAbsent("lock", uuid, 300, TimeUnit.SECONDS);
        if (lock) {
            System.out.println("获取分布式锁成功。。。");
            //加锁成功
            //2.设置过期时间，必须和加锁是同步的，原子的
            //redisTemplate.expire("lock",30,TimeUnit.SECONDS);
            Map<String, List<Catelog2Vo>> dataFromDb;
            try {
                dataFromDb = getDataFromDb();
            } finally {
                //删除锁需要原子操作，使用lua脚本解锁
                String script = "if redis.call('get',KEYS[1]) == ARGV[1] then return redis.call('del',KEYS[1]) else return 0 end";
                //原子删除锁
                Long lock1 = redisTemplate.execute(new DefaultRedisScript<Long>(script, Long.class), Arrays.asList("lock"), uuid);
            }

            //redisTemplate.delete("lock");//删除锁

//            String lockValue = redisTemplate.opsForValue().get("lock");
//            if(uuid.equals(lockValue)){
//                //删除自己的锁
//                redisTemplate.delete("lock");
//            }
            return getDataFromDb();
        } else {
            System.out.println("获取分布式锁失败。。。等待重试");
            try {
                Thread.sleep(200);
            } catch (Exception e) {
            }
            //加锁失败..重试
            return getCatalogJsonFomdbWithLocalLock();//自旋的方式
        }


    }

    private Map<String, List<Catelog2Vo>> getDataFromDb() {
        String catalogJson = redisTemplate.opsForValue().get("catalogJson");
        if (!StringUtils.isEmpty(catalogJson)) {
            Map<String, List<Catelog2Vo>> result = JSON.parseObject(catalogJson, new TypeReference<Map<String, List<Catelog2Vo>>>() {
            });
            return result;
        }
        /**
         * 1.将数据库多次查询变为一次
         */
        List<CategoryEntity> selectList = baseMapper.selectList(null);
        System.out.println("查询了数据库.......");
        //查出所有1级分类
        List<CategoryEntity> level1Categorys = getParent_cid(selectList, 0L);
        Map<String, List<Catelog2Vo>> parent_cid = level1Categorys.stream().collect(Collectors.toMap(k -> k.getCatId().toString(), v -> {
            //1.每一个一级分类，查到这个一级分类的二级分类
            List<CategoryEntity> categoryEntities = getParent_cid(selectList, v.getCatId());
            //2.封装上面的结果
            List<Catelog2Vo> catelog2Vos = null;
            if (categoryEntities != null) {
                catelog2Vos = categoryEntities.stream().map(l2 -> {
                    Catelog2Vo catelog2Vo = new Catelog2Vo(v.getCatId().toString(), null, l2.getCatId().toString(), l2.getName());
                    //1.找当前二级分类的三级分类封装成vo
                    List<CategoryEntity> level3Catelog = getParent_cid(selectList, l2.getCatId());
                    if (level3Catelog != null) {
                        List<Catelog2Vo.Catelog3Vo> collect = level3Catelog.stream().map(l3 -> {
                            //2. 封装成指定格式
                            Catelog2Vo.Catelog3Vo catelog3Vo = new Catelog2Vo.Catelog3Vo(l2.getCatId().toString(), l3.getCatId().toString(), l3.getName());
                            return catelog3Vo;
                        }).collect(Collectors.toList());
                        catelog2Vo.setCatalog3List(collect);
                    }

                    return catelog2Vo;
                }).collect(Collectors.toList());
            }
            return catelog2Vos;
        }));
        String str = JSON.toJSONString(parent_cid);
        redisTemplate.opsForValue().set("catalogJson", str, 1, TimeUnit.DAYS);
        return parent_cid;
    }

    //从数据库查询并封装整个分类数据
    public Map<String, List<Catelog2Vo>> getCatalogJsonFomdbWithLocalLock() {

        //1.如果缓存中有就用缓存的
//        Map<String, List<Catelog2Vo>> catalogJson = (Map<String, List<Catelog2Vo>>) cache.get("catalogJson");
//        if(cache.get("catalogJson")==null){
//            //查询数据库
//            cache.put("catalogJson",parent_cid);
//        }
//        return catalogJson;
        synchronized (this) {
            return getDataFromDb();
        }
    }

    private List<CategoryEntity> getParent_cid(List<CategoryEntity> selectList, Long parent_cid) {
        List<CategoryEntity> collect = selectList.stream().filter(item -> item.getParentCid() == parent_cid).collect(Collectors.toList());
        //return baseMapper.selectList(new QueryWrapper<CategoryEntity>().eq("parent_cid", v.getCatId()));
        return collect;
    }

    private List<Long> findParentPath(Long catelogId, List<Long> paths) {
        //收集当前节点id
        paths.add(catelogId);
        CategoryEntity byId = this.getById(catelogId);
        if (byId.getParentCid() != 0) {
            findParentPath(byId.getParentCid(), paths);
        }
        return paths;
    }

    //递归查找所有菜单的子菜单
    private List<CategoryEntity> getChildrens(CategoryEntity root, List<CategoryEntity> all) {
        List<CategoryEntity> collect = all.stream().filter(item -> {
            return item.getParentCid().equals(root.getCatId());
        })
                .map(item -> {
                    //1. 找到子菜单
                    item.setChildren(getChildrens(item, all));
                    return item;
                }).sorted((menu1, menu2) -> {
                    //2.菜单的排序
                    return (menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort());
                })
                .collect(Collectors.toList());
        return collect;
    }

}